In a large frying pan over medium heat, melt butter with oil. Add chicken and brown both sides. Remove chicken from pan. The chicken does not have to be cooked though, just browned
Stir flour into pan juices. Cook, stirring for 1 minute without browning. Stir in chicken broth and white wine. Add chicken back into sauce. Cover and simmer for 15 to 20 minutes until chicken is tender. Remove chicken to a plate and cover to keep warm
Whisk mustard and cream into pan juices. Add chicken back in. Simmer for 3 minutes. Serve